Wales wing Mark Jones went over for a hat-trick of tries as the Scarlets made the Dragons pay for fielding a below-strength side in the Celtic League at Stradey Park.
Jones claimed a 13-minute hat-trick in a dominant first half for the west Wales side which takes them one step closer qualification for next season’s Heineken Cup.
For the Dragons, their hopes now rest on securing an end-of-season home play-off against an Italian side.
Their coach Paul Turner had made 13 changes from the side beaten by Cardiff Blues in midweek with many of his side having hardly sampled league action this season.
In contrast, Scarlets chief Gareth Jenkins selected from strength, and it showed.
After a scrappy opening it was Jones who set his side in motion with a blistering 70-yard try after 15 minutes.
He followed that up with a short-range effort from Matthew Watkins’ cross-kick and then claimed another quickly afterwards.
The Dragons were again guilty of turning over ball inside the home half and when put in space there is no better finisher in the Welsh game than the Llanelli flyer.
Jones first cut inside scrum-half James Ireland and then pulled away from half-back partner Aled Thomas to become the first Llanelli player to claim a hat-trick in Celtic League rugby.
The Dragons managed to respond with a Leigh Hinton penalty after 33 minutes, but it was not long before the Scarlets were running in their fourth score.
This time skipper Dafydd James was given the chance to stretch his legs on the other wing and he made no mistake to notch up the bonus point.
The Dragons introduced skipper Jason Forster at the turn-around, but he could no little to stem the scarlet tide.
Wales full-back Lee Byrne was next over the whitewash, capitalising on more smart work by the home midfield, then James claimed his second following more neat work by Watkins.
The Dragons did manage to add some respectability to the scoreline with late tries from the impressive Nathan Brew and replacement Jason Forster.
But the Scarlets were never going to be denied and they leapfrog Border Reivers to move up to seventh in the table.